/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.constant.visitor;

import proguard.classfile.Clazz;
import proguard.classfile.attribute.*;
import proguard.classfile.attribute.visitor.*;
import proguard.classfile.constant.*;
import proguard.classfile.util.SimplifiedVisitor;

/**
 * This ConstantVisitor and BootstrapMethodInfoVisitor travels from any invoke dynamic constants or bootstrap method
 * info entries that it visits to their bootstrap method handle constants, and applies a given constant visitor.
 *
 * @author Eric Lafortune
 */
public class BootstrapMethodHandleTraveler extends SimplifiedVisitor
    implements ConstantVisitor, AttributeVisitor, BootstrapMethodInfoVisitor {
    private ConstantVisitor bootstrapMethodHandleVisitor;

    // Field serving as a method argument.
    int bootstrapMethodAttributeIndex;

    /**
     * Creates a new BootstrapMethodHandleVisitor that will delegate to the given constant visitor.
     */
    public BootstrapMethodHandleTraveler(ConstantVisitor bootstrapMethodHandleVisitor) {
        this.bootstrapMethodHandleVisitor = bootstrapMethodHandleVisitor;
    }

    // Implementations for ConstantVisitor.

    public void visitAnyConstant(Clazz clazz, Constant constant) {}

    public void visitInvokeDynamicConstant(Clazz clazz, InvokeDynamicConstant invokeDynamicConstant) {
        // Pass the method index.
        bootstrapMethodAttributeIndex = invokeDynamicConstant.u2bootstrapMethodAttributeIndex;

        // Delegate to the bootstrap method.
        clazz.attributesAccept(this);
    }

    // Implementations for AttributeVisitor.

    public void visitAnyAttribute(Clazz clazz, Attribute attribute) {}

    public void visitBootstrapMethodsAttribute(Clazz clazz, BootstrapMethodsAttribute bootstrapMethodsAttribute) {
        // Check bootstrap methods.
        bootstrapMethodsAttribute.bootstrapMethodEntryAccept(clazz, bootstrapMethodAttributeIndex, this);
    }

    // Implementations for BootstrapMethodInfoVisitor.

    public void visitBootstrapMethodInfo(Clazz clazz, BootstrapMethodInfo bootstrapMethodInfo) {
        // Check bootstrap method.
        clazz.constantPoolEntryAccept(bootstrapMethodInfo.u2methodHandleIndex, bootstrapMethodHandleVisitor);
    }
}
